1. Field of the Invention
The present invention relates generally to a container base for enhancing the structural integrity of the base.
2. Related Art
Plastic containers, such as polyolefin containers, can be used for packaging snack dry food. It is understood by a person having ordinary skill in the art that to form such polyolefin containers, a parison can be heated in an extruder, captured by a mold, and blown in the mold. Specifically, to form the cavity of the container, a parison can be extruded up into the mold and as the mold comes together, a pneumatic blow pin, for example, can pierce the parison and blow the parison up against the walls of the mold. The mold typically contains flash pockets above and below the cavity in the mold to capture the excess parison above and below the cavity. It can be understood by a person having ordinary skill in the art, that as the parison is blown inside the mold and captured in the flash pockets, portions of the parison must adhere together. Once the container is cooled, the excess flash can then be cut away from the container after being ejected from the mold.
Dry food containers can be filled at altitudes at or below sea level and then fitted with an airtight seal. When these containers are subsequently shipped, they must be able resist deformation caused by changes in external air pressure that can cause changes in the internal pressure of the container. For example, when the containers are shipped at high altitudes, e.g., across mountains, the external pressure can drop such that the containers have an increased effective internal pressure.
Such an increase in effective internal pressure can cause the bases of the containers to distort. Often times, an inner portion of the base will distort below the intended bearing surface of the base. When such distortion occurs, the container tends to rock on the inner portion of the base instead of standing upright on the bearing surface of the base.
What is needed, then, is a plastic container having a base design that is capable of withstanding changes in pressure without distortion below the bearing surface of the base.